Issue during the configuration of SeedLink 4

[nchazarra]

Dear Andres, we have tried using the new module but face a very odd problem when building.
Having done it a few times and very carefully to make sure to follow the steps correctly, it always gives the following error.
Can you have a look? Thank you kindly.

[ 94%] Built target scrttv
[ 94%] Built target scshowevent
[ 94%] Built target nuttli
[ 94%] Built target test_mn_amplitudes
[ 94%] Built target seiscomp_mvx
[ 94%] Create version header in /home/nchazarra/seiscomp/build/src/base/mainx/apps/gui-qt/scmvx/version.h
[ 94%] Built target scmvx_version
[ 96%] Built target scmvx
[ 97%] Built target gmsexample
[ 98%] Built target slplugin4
[ 98%] Built target slutils4
[ 98%] Create version header in /home/nchazarra/seiscomp/build/src/base/seedlink4/apps/seedlink4/version.h
[ 98%] Built target seedlink4_version
[ 99%] Built target seedlink4
[ 99%] Create version header in /home/nchazarra/seiscomp/build/src/base/seedlink4/apps/sl3plug/version.h
[ 99%] Built target sl3plug_version
[100%] Built target sl3plug
[100%] Generating libslink4/libslink.a
make[3]: *** No se especificó ningún objetivo y no se encontró ningún makefile.  Alto.
make[2]: *** [src/base/seedlink4/libs/3rd-party/CMakeFiles/buildslink4.dir/build.make:73: src/base/seedlink4/libs/3rd-party/libslink4/libslink.a] Error 2
make[1]: *** [CMakeFiles/Makefile2:13874: src/base/seedlink4/libs/3rd-party/CMakeFiles/buildslink4.dir/all] Error 2
make: *** [Makefile:166: all] Error 2

[nchazarra]

We finally managed to compile SeisComP with SeedLink4, but unfortunately we are not able to start the server:

OS: Ubuntu 26.04 LTS / Linux
2026/05/22 14:29:00 [error/Application] Fetching database parameters failed, no messaging connection
2026/05/22 14:29:00 [notice/Application] Shutdown

We had the same problem using the three supported database systems (MariaDB, PostgreSQL and SQLite)

@andres-h could you point us to what we can be missing? Regular SeedLink server and client works.

[andres-h]

Dear Nahúm, first of all I apologize for not responding to your previous message. I did not get a notification. The problem was apparently due to missing submodule initialization step.

The database issue is due to missing database url. Since seedlink4 does not use messaging, you have to define database in global.cfg or seedlink4.cfg:

database = mysql://user:password@localhost/seiscomp

(assuming MySQL)

[nchazarra]

Thanks for your help. With this information we finally managed to load the plugin, but we are still unable to receive data through SL4.

We have tried both to do a clean setup with SL4 and a MSEED3 station, and also a working SL3 configuration migrated to the new SL4. Interestingly, the stations that were working in SL3 don't even receive any data using SL4.

These are some of the observations we made:

• When starting SL3plug the old seedlink module starts again automatically.
• At some point we saw an error mentioning station TEST123 when the station name is TEST1234. So we are wondering if there is a problem with long station names.
• In scrttv the error console shows error SLConnection "Connection or handshake with localhost:18000 failed. Trying to reconnect every 0.5 seconds." but our server is not running locally.

We are not sure how to debug this properly, please let us know what information can we provide.

Thanks again.

[andres-h]

When starting SL3plug the old seedlink module starts again automatically.

The seedlink module is marked started, but the actual process is sl3plug. This is to prevent starting seedlink and sl3plug at the same time, because both run the same plugins. Maybe we will find a better solution in the future.

At some point we saw an error mentioning station TEST123 when the station name is TEST1234. So we are wondering if there is a problem with long station names.

There is no problem with long station names from seedlink4 point of view, but there are likely limitations in sl3plug, which tries to be compatible with all existing plugins. In fact, all our miniSEED 3 test data is converted from miniSEED 2.x with standard station names. Which is your intended data flow?

In scrttv the error console shows error SLConnection "Connection or handshake with localhost:18000 failed. Trying to reconnect every 0.5 seconds." but our server is not running locally.

scrttv uses the recordstream that is defined in configuration. You can define it in global.cfg, scrttv.cfg or use the -I commandline parameter.

[andres-h]

To get miniSEED 3, you actually have to use the new slink4 recordstream, which will be available in the next SeisComP release (or use the main branch/nightly build). Likewise slinktool does not support seedlink4 yet and only shows miniSEED 2.x streams.

[CarlosGS]

Thank you Andres. We are developing an Open Seismometer, and using directly Mseed3 (instead of MS2+conversion) truly optimizes resource usage. So it is fantastic news to see support in SeisComP :)

To go step by step, so far we haven't even been able to transition from the original seedlink module to the new seedlink4. The traditional setup works and data appears, but following the instructions and just stopping seedlink and starting sl4+sl3plug, no data appears in scrttv anymore.

scrttv uses the recordstream that is defined in configuration

Should we change anything when migrating from a working seedlink configuration?

[andres-h]

Sorry about the delay, just back from a short vacation.

To go step by step, so far we haven't even been able to transition from the original seedlink module to the new seedlink4. The traditional setup works and data appears, but following the instructions and just stopping seedlink and starting sl4+sl3plug, no data appears in scrttv anymore.

Which plugin does the traditional setup use? I'm confused, because traditional setup means MS2 and simply switching to sl4+sl3plug does not convert data to MS3 even if SeedLink 4 is used. You would need MS3 source and chain4_plugin to get MS3.

Alternatively, it is possible to push MS3 data to the seedlink4 module directly without using sl3plug. This option is currently not documented, but you can use the FEED command (from localhost or trusted IP) and then start feeding SeedLink 4 packets (use -1 or 0xffffffffffffffff as sequence number). This is a better option for new projects that do not need backwards compatibility.

Should we change anything when migrating from a working seedlink configuration?

Should be just things I already mentioned above:

• Define database connection, eg., make sure you have
  database = mysql://sysop:sysop@localhost/seiscomp
  or equivalent in ~/seiscomp/etc/seedlink4.cfg
• Use slink4:// recordstream, eg.,
  seiscomp exec scrttv -I 'slink4://localhost:18000' --debug
  or add to ~/seiscomp/etc/global.cfg:
  recordstream = slink4://localhost:18000

For debugging purposes, try to run in separate windows:

seiscomp exec seedlink4 --debug
seiscomp exec sl3plug -v -f /home/sysop/seiscomp/var/lib/seedlink/seedlink.ini
seiscomp exec scrttv -I 'slink4://localhost:18000' --debug

Until the next SeisComP release, the slink4 recordstream will be only available in github main branch and nightly builds. slink4 is required for MS3 support.

[CarlosGS]

Hi Andres, with your help we were able to get SeisComP running with Mseed3 :)
I think we missed adding recordstream = slink4://localhost:18000

We will do more testing and get back with any findings, but so far it works very well. Awesome to have this working in SeisComP!
Thank you very much!